Rabbi Professor Moshe D. Tendler is a rosh yeshivah of the Yeshiva University-affiliated Rabbi Isaac Elchanan Theological Seminary (RIETS). He is also a professor of biology at Yeshiva College, and the Rabbi Isaac and Bella Tendler Chair in Jewish Medical Ethics at Yeshiva University.

Rabbi Tendler was ordained at RIETS in 1949 and earned a PhD in biology from Columbia University in 1957. From 1973 to 1982 he served on the Medical Ethics Task Force of the Federation of Jewish Philanthropies, for which he edited The Hospital Compendium of Medical Ethics and Halakhah. For two decades he served as its chairman. He was also chairman of the Bioethical Commission of the Rabbinical Council of America. He has been a member of the board of directors of Americans for Medical Progress Inc. and is a member of a number of ethics commissions. A former president of the Association of Orthodox Jewish Scientists, Rabbi Tendler is the author of Pardes Rimonim (a text on Jewish family life); Practical Medical Halakhah; and Care of the Critically Ill-Responsa of Rav Moshe Feinstein; as well as many articles on science and religion in leading publications. He is frequently consulted by the media and public officials on ethical issues.

Rabbi Tendler has been one of the most vocal and adamant supporters of Jewish organ donation. The son-in-law of Rabbi Moshe Feinstein, Rabbi Tendler has interpreted his father-in-law’s responsa to support the theory that complete and irreversible cessation of function of the entire brain renders a person “physiologically decapitated”, and is considered legally dead according to Jewish law. Thus, Rabbi Tendler has been a strong advocate for brain death criteria to be adopted as an acceptable definition of death under Jewish law. According to this opinion, removal of organs for donation, including vital organs such as a heart that may still be beating, is permissible upon pronunciation of brain death. Furthermore, Rabbi Tendler asserts that once organ donation has been deemed permissible under the given conditions, it is indeed mandatory, falling under the rubric of the legal obligation of Jews to preserve the lives of others.